Pain in left testicle from 6 yrs. I do!

I am experiencing mild pain in my left testicle from last 6 yrs it is not a constant pain it comes and goes and the time period the pain stays is around 3-4 days and along with testicular pain i also experience pain in my lower abdomen and lower back mostly what i have noticed till now most of the times the pain comes after 1 or 2 days after i ejaculate but sometimes there is no pain even 7 days after ejaculation and sometimes i experience pain when i have gas also ,I have already done ultrasound of my scortum and my bladder and kidney nothing abnormal found i also have done blood test for viral infection and everything was normal my urologist told me that during urinating some amount of urine is leaking inside my testis which is creating infection which is causing pain but if urine is leaking inside my testis then it could go to my right testis also as both have a same path but i had never experienced pain in my right testicle what should i do